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arXiv · 2503.18519

Effective field theory for weakly bound two-neutron halo nuclei: corrections from neutron-neutron effective range

Davi B. Costa·Masaru Hongo·Dam Thanh Son
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Abstract

Using an effective field-theoretical approach, we investigate the properties of weakly bound two-neutron halo nuclei (also known as Borromean nuclei) that do not support a low-energy $s$-wave core-neutron resonance. Extending the recently formulated effective field theory for weakly bound Borromean nuclei, we incorporate corrections arising from the effective range of neutron-neutron scattering and evaluate their impact on the mean-square radii and electromagnetic response. In particular, we compute the ratio of the matter and charge radii, the shape of the $E1$ dipole strength function, and the electric polarizability. Our results indicate that these corrections remain numerically small when the two-neutron separation energy of the Borromean nucleus is much less than 1~MeV.

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Davi B. Costa, Masaru Hongo, Dam Thanh Son. 2025-03-24. Effective field theory for weakly bound two-neutron halo nuclei: corrections from neutron-neutron effective range. https://doi.org/10.1103/lds3-g3tp

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